How the interaction occurs:
Aluminum, lanthanum, magnesium, simethicone, and sucralfate may bind to your thyroid hormone in your digestive tract, preventing your body from absorbing your medicine.
What might happen:
A decrease in the beneficial effects of your thyroid medicine may occur.
What you should do about this interaction:
Try to time your medicines so that you take your thyroid medicine at least 4 hours from may medicines that contain aluminum, magnesium, simethicone, or sucralfate or at least 2 hours from lanthanum. If you have any questions about how to schedule your medicines, ask your pharmacist.If you experience fatigue, sluggishness, constipation, stiffness, muscle cramps, loss of appetite, weight gain, dry skin, or difficulty in cold weather, contact your doctor.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Synthroid (levothyroxine sodium) US prescribing information. Abbott Laboratories June, 2011.
2.Fosrenol (lanthanum carbonate) US prescribing information. Shire US Inc. September, 2014.
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